If you're on the internet, as most of you are (except Steve; I have to print my posts and send them to him by carrier pigeon), you've no doubt seen (and been bugged by) vertical videos— videos that are about 66% letterbox because they were taken by some nob who couldn't figure out how to hold their phone correctly.
So imagine my surprise when my own father sent me a vertical video he took. And then another. He clearly knew better— he insisted quite vehemently that he definitely took the videos correctly and had no idea why they came out the way they did.
Then for the first time, I finally got a chance to actually look at his mobile to ascertain the problem. The problem? He has a completely idiot-proof phone whose makers attempted to combat VVS by physically building the camera "sideways" so that when people held their phones upright while recording, they end up with proper horizontal videos. Unfortunately, because my father knows better than to record vertically, he made a point of turning his phone— and, of course, ended up with vertical videos because the "idiot-proof" sideways camera records vertical videos when the phone is held correctly.